Zn(II)-Coordination Polymers with a Right- and Left-Handed Twist: Multifunctional Metal–Organic Hybrid for Dye Adsorption and Drug Delivery

Abstract

A relatively less explored bis-pyridyl-bis-amide ligand (L1) having a diphenylmethane backbone was exploited to generate a new series of coordination polymers as potential multifunctional materials. The reaction of L1 with ZnCl2, ZnBr2, CuCl2, and CoCl2 resulted in four coordination polymers, namely, CP1 [{Zn(II)(μ-L1)(Cl)2}·H2O]∝, CP2 [{Zn(II)(μ-L1)(Br)2}·H2O]∝, CP3 [{Cu(II)(μ-L1)4(Cl)}·Cl·H2O]∝, and CP4 [{Co(II)(μ-L1)4(Cl)2}]∝, which were characterized by single-crystal X-ray diffraction. While isomorphic CP1 and CP2 were one-dimensional (1D) coordination polymers displaying a right-handed and left-handed twist, respectively, CP3 displayed a three-dimensional coordination network having open channels that were occupied by chloride counterions and MeOH solvates. CP4, on the other hand, was a 1D looped chain coordination polymer. Both CP1 and CP2 were found to be a good adsorbent of organic dyes with an increased affinity toward anionic dyes. Powder X-ray diffraction studies revealed that the dye adsorption occurred at the surfaces. CP1 was also able to adsorb an anticancer drug, namely, doxorubicin hydrochloride, and deliver it to the target cancer cells MDA-MB-231 as revealed by a cell migration assay and cell imaging studies.